1. Field of the Invention
The present invention relates generally to model aircraft; and, more particularly, to toy gliders which have motion imparted to them by a user's hand or by a launching device such as a catapult or by any other device capable of imparting motion. The present invention also relates generally to mechanically or electromechanically remote controlled model aircraft.
2. Description of the Prior Art
A purchaser of a model aircraft, such as a toy glider or remote controlled model aircraft, normally will choose only one of many possible aircraft configurations and planforms. The heretofore standard configuration has a main fuselage which locates a primary lifting surface toward the front of the fuselage and vertical and horizontal stabilizers at the rear of the fuselage. Each particular configuration and planform has its own aerodynamic characteristics. For example, one particular configuration and planform may enable the model aircraft to make excellent loops while another configuration and planform may enable the model aircraft to fly straight for a considerable distance. Still another configuration and planform may enable the model aircraft to reach a high altitude or fly fast. Each model air craft has its own particular aerodynamic advantages and disadvantages. The purchaser of a model aircraft will normally select one with a particular configuration and planform at time of purchase. Consequently, the purchaser must purchase more than one model aircraft to obtain varied desirable visual appearances and aerodynamic characteristics.
The most salient differences in model aircraft usually arise in the relative size and shape of the fuselage and the relative size, shape and placement of the lifting and stabilizing surfaces on the fuselage. The fuselage of a model aircraft is generally cylindrical and its shape resembles that of a fullsize aircraft. However, the fuselage may have various other shapes, for instance, it may be thin and pointed or wide and blunt. The shape and other features of the fuselage facilitate the placement of aerodynamic structural members, such as the primary lifting surface which in turn determines the final aerodynamic characteristics of the model aircraft.
Just as there are a wide variety of fuselage sizes and shapes available, there are also a wide variety of primary lifting surface sizes and shapes available for model aircraft. For instance, the primary lifting surface may have a swept delta shape or a straight full span configuration. In addition, the placement of the primary lifting surface on the fuselage may vary from model to model. The placement and shape of the primary lifting surface has a very pronounced effect on the visual appearance and aerodynamic characteristics of the model aircraft. Thus, the shape of the primary lifting surface and its placement on the fuselage is another factor which the purchaser must consider when chosing a model aircraft.
Other important contributing factors affecting the visual appearances and aerodynamic characteristics of the model aircraft are the stabilizing surfaces. The placement of the stabilizing surfaces has a pronounced effect on the appearance and handling characteristics of the model aircraft. An empennage may have one or more vertical stabilizers or none at all. Obviously, the number and size of the stabilizers or their absence can severely affect the appearance and yaw stability of the model aircraft. Moreover, the stabilizing surfaces can have various configurations and placement locations on the fuselage further affecting the appearance and aerodynamic characteristics of the model aircraft. Stabilizing surface variations can be similar in scope to the variations in the primary lifting surface. Thus, the configuration and placement location of the stabilizing surfaces must be considered by the model aircraft purchaser when selecting a model aircraft.
The purchaser should be knowledgeable in order to make an informed decision with respect to the purchase of a particular model aircraft. However, especially with toy aircraft, the typical purchase does not have sufficient aerodynamic expertise to make such a decision from all the possible choices. Neither is it typically practical or feasible to personally flight test each toy glider to see if the characteristics are those desired. Indeed, extensive trials of each glider may be required in order to determine if the glider is or is not suitable.
Thus, the purchaser has no alternative but to buy a model aircraft and then test it later to see if it is suitable. Available model aircraft usually have little or no design variability. Model aircraft typical provide little or no adjustment of the placement of the primary lifting surface or of any of the other components which together define the aerodynamic characteristics of the model aircraft. Consequently, the purchaser cannot significantly alter the configuration or planform of the model aircraft after the purchase. These and other disadvantages are solved using a multiple configuration model aircraft.